SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69662388e18a705f05fcecf9a131ae1f5099805baaac379fb2d926f29e4993f' 
  AND token = 'B3oaWRJggvxAdvyOvRzE/1e0xiRMBfXp5hwkj4eePXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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