SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad5afaa1eb4d5026009c06a49de69d88d0ece1db38fda0ef7dc1e1e248636986' 
  AND token = '0i/fSpMhFaWVhUgMVztBP2hI5pEoxdrFBGhIHxXerdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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