SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '703bf06c4ab1dbbe4db93519bb5f6339fc872bf92d680e9b38a6063d84a3d24b' 
  AND token = 'HbBnd193K4vSf06Nf+B5lFSfe99W3DVPoyigyK27u8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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