SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0367cadd9c952ec8030c67ad2f2c6650eab5e0d2f767d87746cf9ba3499f8742' 
  AND token = 'Tp5K1xASq0xMXALvr9uqAY6vXMCLSXSUejrNFri9upg=' 
  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"
    }
  }
}