SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a74a6687a17948c6d7fe529c3aeb9e20dc18c291dd515815f6b74c101edf59a' 
  AND token = 'GHK5xZN2YltJOkeRnZt69gbtl8XmNn7DKkEHv6H6JJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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