SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9864161c981ded749233fa94c3b48f048fe94fd1c04fe0af84c5dab7af88420b' 
  AND token = 'p/OJZLBsZnzXFGNuu4e4kbtJeVaVsNqgunaGD36fEcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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