SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '68a184cfbf06e858eacf6d70c8998610582763b2f8475f6311f3b8ef8f24de0a' 
  AND token = 'KH+b0RN8aa3vZHFynP5zHm/GUqWy/Lfen7GaX7/7qQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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