SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa6339bebd261200f1d4395eb6181338db4ad663acbb4224d3ceb050c642cc27' 
  AND token = 'PJZHVK7kWtU6EcbW5juFA6dbi8vgwxvmOI3Ihlhl4GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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