SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edd799c8f05049dad8be18fc029896008bf9f4fe56398a5a5b3439f1983493e9' 
  AND token = 'n4aEfOrsumAX/cX0QCqch6pafWKZdoOjfWoKKppsnsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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