SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '069bf5235d30a313e5b6bf12ed74ea84a22d296417549f16e094499aa9b7b957' 
  AND token = 'qQLXbvg/SF85JwqAs3edXoYPb/uqYjYCgzPjk/MtbiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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