SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd8e5fcab6ee9517fbda9ca81761dd2bcdc21b21a1fe54d4678b48dbde43c396' 
  AND token = 'vgQ0vpQrptN7fp5Uv8O25svuywwvYFvuxoEDA6hYOrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00106

JSON explain

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