SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccdd4744b796acd21f8021ac530f28131b9cc089b4790074bd48ed611bce78d4' 
  AND token = 'gKinsBMEm1Oq8Twibkq5eGMmq1M03RXm+pR5Ad6W09A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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