SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a830b35d12967520923926e7cb5b08e27c9734e57a3cfdb5828479c790988a' 
  AND token = 'M7b8bjp86WkwCtX1MqYYS/wYozxgjJY+r7G86jmRcWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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