SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db97be8f97c95f3714ab328a406288f015515281d306d260492c75d094918edc' 
  AND token = 'x/m6JKIvY8Zy6AgCS1ryQLKN4ViEhs+l2BCEoFc4+Wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}