SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680f97c3624f82575b1fbfe9784e7a8a763df3e75114b50c8ddfc6ac4698044d' 
  AND token = '4v0eFXvlzoXB9QCQ+gnstapHkioxbgU5gUFoBBG7bCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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