SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acdde02902a0f0cbc72e3fbbbaca8e7f9f06e2ea8512bf943bfa92596bbcea76' 
  AND token = 'C6lHkBrgGAX2mtJlfuo7dLw73iWdkEwxmbBR62bIu8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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