SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0eedccc2c7891faff4140b96499a18798fb2fd3a645ea6dc28c934f5b6f63f1' 
  AND token = 'sCFERlxokjVpzhqNhhZmeMxiuokgd7lwDLrcVuilw08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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