SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '802e4905cba196e66a229afce941e373f4a42ee9565c8ba3550a523f90b4793b' 
  AND token = 'LMh3FxD+JeCBKK/BJXdScUxYvDiTjf1S598RAvlQzzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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