SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fb2821ac917b462a8aa94d91cd170c9debd774bfbabcf875e6ead55b54cfd8b' 
  AND token = 'YmR1vlM0VOeuezg22R7fKdpyadXGAEZH8jtacdcpPeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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