SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a302625a377d9c1c6baca42abefbc970629dd3a96a135c4fe36e9338f05138a2' 
  AND token = '7HYzj3HNIL5hVe4hXVUwYKvAAb15eGZZaRsKzjQy3j8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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