SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98fd53aada2cd1aab2f8126d4489016c6d08b0aa0907234f247fbf58c4799427' 
  AND token = 'WcPpaQXMtEfW8k1HnCgj3+W5qTH65W2/5cePhQRAKDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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