SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba96cf8607642a560905c7bd77c3931855ab85440553d4b43626300928aaad68' 
  AND token = 'IxgBmioR/TMEtN/HBjP2VV4sA5tI1w3TEs10FPZgPtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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