SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff9d942a6d4e298ceab16d744e2ceb1deebf47333ff0d3c16559603251861ed7' 
  AND token = '3uJU4SnaQD7VgeGqH2pipnn9q9Oz4Zf30iNKfZcea74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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