SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34a8c0f9e4bab562f3b608ab35391ab09a93476c3143e2d45db1737bf0da7a77' 
  AND token = 'I6hhG2x5FoJ4m0T09nGJsHjWZCdM7EDCuZqPbCCHMP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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