SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99740cf324148d4af0d1f668edc933e741c438f0cf63699031c9c14ad8689380' 
  AND token = 'Zt1FPLUXYGBqhF43V1I2WOxhVSc3g4n6GsNfkaep02s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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