SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4433c0b9647d5eb7cece3c44a7e8deb201c3e3d0243cb9e8e9b6a1ee4cca2e75' 
  AND token = 's7hmxmcOdbXCpWJ0CnY4aPwfs23io9mDbnPOuaHsfpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}