SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2981135ee4903bdef514d2431d88e7f42872aeaadea7b706dbeb57d43086931a' 
  AND token = '51166e954aaYI6ubo8z5SLSPbLxudpADHI0ExWCzuRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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