SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b3a7f79728f532afa27e4f49d794acb568362958217481bea6ee181b4f3d1d5' 
  AND token = 'kFDpbleqpaOqS7CSPNIFW1kdxLZPn3mwTLADi+/4yJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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