SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f0fc772448544ab93e9ae240b8f32fd302450d2349d3589e9b6711fd689383a' 
  AND token = 'ulwGVst7tumzn1Z5r7bTeK+oOPBhDN2WgmGmmb6wyLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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