SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f2f3cbf4d30e504368835e843f8bd9cff5fe79186b37f134040104ef718935a' 
  AND token = 'qjnsWmY5rTlAPhAOzvzNwN6vszXSF+k5VhzsvCUUfZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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