SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1d02d11fb719400ca23c396e82eecb49f34ec7ec916d5ab2560f5efac088f9d' 
  AND token = 'yPjYAn6ZtFPIVPwWgf3PR+HuXUe5Esv5SRtuosgkWjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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