SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '229c8fc2a1119c755baa46c465f64eb44c578a5f4571933656dce41c3fbb67ca' 
  AND token = '8WiwlFcXfw8pstZoA7p287pTEPUwQL/HZ2gpoAhCpu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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