SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '408afec77b7ca43b8be5d2b6e7c7f1483c4b57365c8be919e20982bd687bd77b' 
  AND token = 'BnRccVvA/FnSN7V5s/JJhhB2j/0Gj23++3qZWqLxCLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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