SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16d16bb0b08aa342b4676f497886614396c31b0811862cc533f8d39ba98bc554' 
  AND token = 'gbzq9JA7Y7d5UHWSODD/78Lf3DR3AZlXs05UnDwWTRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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