SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1ee910dc369fead9df52a16077735130caa11035cbef2f6d44a3b675cabfd06f' 
  AND token = '5xNu6xz8kzm6JeFnEWbB0YxRvv9zEGKKOsQr38jr7Ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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