SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45075c43fc4a45a18964daf8f70b7be2b0d461885dc6788e56ab1f47a4ead5f0' 
  AND token = 'Z/q6y0aT7klbyw20fKPxtcFRCmwFiI4kzSvGeMyhXzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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