SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed6c2d3b933bfcbf9f6e47e1acef913ad859697a09629cf4a6a2281548a3629d' 
  AND token = 'PZrYzqPx+TejEKW+RlYT02HJNHmY+jzWKCanSoy9T2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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