SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae9b8daaba171723609cdbff8506ca28e60788933779bf7890015f2299a8ce4' 
  AND token = 'irHXGTWHBALk8yIH79QxE1R2NlCnYp5yZE9vqtsIKy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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