SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e9b5275f16a6987da9e27ab74d19c02b9fcb9d785d8816f9ad5966e54ad5d7e' 
  AND token = 'bMC4huQwJbT6wRBpdYam/GNhj9gLAzXZPhzZnGW7oRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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