SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77d99998e815f94a231f42bf0b701cd317345d010df32ec5fdb30e5a2c49d992' 
  AND token = 'RavCyLuHFZH/605gzVbCT1rLTJoOUbQpsQuQXM4F2RU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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