SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c49da475ec7777994bcbcd645ce48d5285ad7e2fb6b82c9a9c9541cc36316ad' 
  AND token = 'kBxUVAm7h/KzamFD5r76df3pwHcYLkGxwDJG/lfhQIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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