SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04a6d7b7a9fe29817dc97e37fd7781b685ebcfeb3824fd90cf591dd8b1d067d9' 
  AND token = 'N+s220kzybUlBG9CbjzRZJ86jDRXiyITMlREIIi7Or4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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