SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f73e591d0ac2abb9d7eb7764c6f9cf62fa19169e9430bf2d5d94ed05a8441635' 
  AND token = 'q+kwGyqgUmOmwYg0mR5RzfudVFS4hIevXbrE968/MPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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