SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a196dbb16b878e723d2fa7a7b4e572cf9af4fb27d2b9006221a14f6293231d' 
  AND token = 'sIg9YJY6E2p9H5o/CGZX52jZeuzrFrwJmAjlcsA+mD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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