SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd93dfad0fb1527575a206c0fa1675cefe1049d35ee01c8203af8bdd7d31e7677' 
  AND token = 'NthyLONKpTGMilLUc+/fzJhSU/dFCsjha/9Pvz+jYGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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