SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1ff01f00be284c065bcd3fc5d0d1c45377b989754525b7aa063477d541dbc8' 
  AND token = 'cYrMAWn8Lv9r4+LB9gwKX3tyeDXasFvpqUjsXgsL+Tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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