SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f05794e5aad7426b95720b51651de927f0b482384585a2466884c4fd4726423c' 
  AND token = 'bCZTGOgxvgk+XhbAuVdFCxdpYDLBgQzX9s8Sdh8DGg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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