SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cadbfbf7ecb27cbbed013c652ffc28ffa9f78bac7b05341d64b8fe18d6496cf' 
  AND token = 'WgeexdlUPn0RuD5S89ZwymAAOWcsNixgcvQLI2iwS14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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