SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd954cf2739d77f345b7dc2b9c9879da781f6f43740d5cfadf556fcbfab80472' 
  AND token = '6nq5m+C7BilxQYzDbn/bWT3ISJrMIEgxVWQz1VDeWDU=' 
  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"
    }
  }
}