SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ae8bee3a956d9e0a8a458a758f11ef56bb333fddac4d1995fb500e5f3ebdd0' 
  AND token = '6alibabt0dOB0hGTNL2PB0YfAfxkfIDC3UoqqRJPtIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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