SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ab114adf7f61507748f850313eb1659eec0b8f1931c9e930327b8ed64de2a49' 
  AND token = 'Z+jPuhlsE+ZBULFqqrb4V+Ue/dCCcvionojdziGVGXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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