SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a95c21aa6335a072e5a11579cc3a1ac23523b834b8da89727f1934b8a2aaf6ed' 
  AND token = 'yVvsDo/MGs1sRhUoLL3N41UYKFjb9PkefCc09oCqIbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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