SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26a15c330820d146fb0ce7ab9b57e3b6512a60e47a0e9e0c71880f645027dc84' 
  AND token = 'AbaV/h7ncHE2/dI5CRmOh8Fsq5wXk8oi6+Bq5KEmfa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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