SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37fb445b9ce15bb69e2d0da34566d08041a7a6f600591e36a9a531c99b4a15fa' 
  AND token = '+/LPiTN+g8hdPMhVLq7WwcV7pGow8qZvav18Z/3CKxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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