SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b359defbad44b71257820d73bb38c616286998e5637fd4cbdef31380bed78dd1' 
  AND token = 'gZUwLE70FbKbwaPDnHZWZK65Sgq4rMw2mWrYjIVGl7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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