SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca02b4980129ea0f8953eb85875b573944aaacc6252e77b16942790986e3a78' 
  AND token = '1HFI7d+qELUfTNTcmzJIITLYjaHFNP/UB0MsLCwjraw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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