SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f247cdff7527698a505ae505fd3c77ccbf7fcb8f37a8905af87c6eadea23d8f0' 
  AND token = 'rJvteEU29JkzuB1VEn3BwabLciPuwtWQ56aBpGbEGTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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