SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea237ed6d5391f9f48c5ff78456fd21821a6715c34376254c7a4fa419b40c610' 
  AND token = 'b1SvCkjm5ZbBwfmyusIIyKuxEbvtFyuZC8aziXfIArA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}