SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2cee0875edc03388794d5476bcf9b696ea3470a942d69abe422ba5225880a78' 
  AND token = 'egfuva5cxA7IFYTmUtxpWE893yDlofc4LwQOHvsMcQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}