SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b9e3eb1845a5102e74805474f793a4de694765a25e7f3c5df634b4d550f7178' 
  AND token = 'WZKosZ8Y/fGTdOZChiiOqh5vUMjwVKX8yLGapjAofs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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