SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a4c4aaa9cbaa7e8e8c7f7e73f887d8959369f59a390b48685d04bd324af2ed0' 
  AND token = 'nlcwNAanHO2xuSz6VsRISgxZeN+YduklJjAsSmfzjqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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