SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf4d256406d6c4800116f8de2a5a6b0838d8444dedc9375d462f90b6bc0d0d4' 
  AND token = 'tDNwBvZPSnglU/jgdwrsZ1+J5I/AGZhczq2StE1IFDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}