SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '419357997e9427a2874b3fd8701e2604af186cdf6ce7e337e96647a10a634c03' 
  AND token = 'k1apTeJo2XmNlHOkrFalttRQ+MRUvY0H1Wf7xnnKank=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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