SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '106596c130fb067da2d3c64fde50a5788137ccb313ff07576c25e3ed543e7db5' 
  AND token = 'rWYVz3hhCOzFP5oXbMAbE2kBVAa4ylKEextMst9I45k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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