SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e3ddfa770b812782c24b5deb76b560821c1af7ae6b31629dab2899aa71b0ca9' 
  AND token = '+U/JjuClO0319UucaWk4L4REgJb1gUreVczEqlsIAG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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