SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e17faaad212ceadaa6667bb8558e60263369712bb1a90fe71ef34d7ce4da5a08' 
  AND token = 'iLk3ri0Mjj7IPQm50dD97dzLuRTCeMPIH1ePL3Juw3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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