SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce92bd1e04b79a7d2944cee522ff1d1cb4308692873f1d0bfed41f0a2c3afd79' 
  AND token = 'wzvJSDFesjNh6PniJCqm6CvAbdY8G6mjj6GUe4EaPVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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