SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '374f433f07a11305fbe85dffec89b1034b99234f449252a80541dd2f79c241dd' 
  AND token = 'v5G1LrRNXBP3FPuqmKAi2hgxoHMzM+pfx/Z4KXXZd/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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