SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12c763ec6678f95b10ad276a42ad5950ea0e7bf42398134f584c5f80743502bb' 
  AND token = 'wNdVOAtTyCIJOd7bkaulzGK9oCuvt+xpUemPikakmK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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