SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65625c510d7df3de866e060c473989291127d431a47c002a1b23e5801b17ae88' 
  AND token = 'KFMzr18RmN/UwVPo6yAIK9pNWRfgGNpimI6t4SlKqk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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